Reversing-valve for steam-engines



(No Model.)

A. FREEMAN.

REVERSING VALVE FOR STEAM ENGINES.

No. 311,890. Patented Feb. 10,1885.

Wine 5:65,. Inventor NHED rates arriv'r tribe.

ALONZO FREEMAN, OF CONCORD, MASSACHUSETTS.

REVERSING-VALVE FOR STEAM-ENGINES.

SPECIFICATION forming part of Letters Patent No. 311,890, dated February10,1885.

Application filcd June 16, 1884.

To all whom it may concern:

Be it known that I, ALONZO FREEMAN, a citizen of the United States,residing at 0011-' cord, in the county of Middlesex and State ofMassachusetts, have invented a new and useful Improvement inReversing-Valves for Steam- Engines, of which the following is aspecification.

My invention consists in providing the valve-chest of a steanrenginewith a main valve having an opening through it 'for the passage ofsteam, and adding thereto an adjoining and communicating valve-chest containing a reversing-valve having two passages for steam, so arranged inconnection with the main valve and the main valve-chest that by amovement of said reversing-valve relative to the main valve and itschest-ports either end of the cylinder will take the workingsteam, saidsteam passing through one passage in the reversingvalve to operate theengine one way, and through the other passage to operate the engine theother way.

In the use of the word steam as applied to an engine in the followingspecification and claims, 1 mean it to designate an engine propelled bysteam, gas, compressed air, or other motive agent.

It also consists in combining with the valvestem operating saidreversing-valve a mechanism for shortening the stroke of the main valve,thus cutting off the supply of working steam, while the reversing-valveby its movement is changing the direction of the steam and reversing themovement of the engine.

The construction and operation of my invention are illustrated in theaccompanying drawings, of which- Figure l is a vertical elevation of myinvention, except that the valve-chests and valves are in section, inorder to show their ports and steam-duets, the valve-chests beinglocated on the side of the cylinder. Fig. 2 is a top view of the same,(the reversing-lever U omittech) showing the horizontal relation of theseveral parts vertically shown in Fig. 1.

Similar letters refer to similar parts in each drawing, as follows:

Ais the engine steam-cylinder. B is the main valve-chest; O,thereversing valve-chest.

(No model.)

BCis the partition separating the two chests B and C; D, theworking-steam inlet. The exhaust-steam may pass out through an openingin any convenient part of the side of the valve-chest O.

E is the main valve; F,the reversing-valve. G is a port extendingthrough the same, c0nveying direct or working steam through port Z intoport H in valve E, and thence into either cylinder port K and Kalternately when the engine is working in one direction.

Y is the port through which the exhaust steam enters the valve-chest Cfrom chest B when the engine is working directly, the steam passingreadily to said opening Y from the cylinder exhaust-duct K by a spacebetween the sides of the main valve E and the sides of the chest B.

I is a port running obliquely through the reversing-valve F and throughwhich the direct or working steam passes into the valvechest B byopening X and into either cylinderport K and K when the engine isreversed.

J is a channel cut entirely across the reversing-valve F, and whichconveys the exhaust-steaminto valve-chest 0 from the ports Z in thepartition BC, and from port H'in the main valve E in its passage fromthe cylinderduets K and K alternately when the engine is reversed, theexhaust-steam passing readily out of said channel J into valve-chest Uby a space between the sides of the reversing-valve F and the sides ofthe valve-chest G.

M is the main valve'stem. iug-valve stem.

0 is a hinged fulcrum-bar, hinged at its inner end to some suitablepoint below the line of the valve-stem M, its outer end. supporting thelower end of the hinged lever B, which lever passes through an eye inthe sliding piece 1', (which is an extension of the valvestem M,) whichslides in the slide-groove h.

Z is an upright piece, which extends upward from the horizontalsupporting-bar R and secures the piece with the slide-groove h.

c is a pin passing through the upper end of the lever P and engaging theeccentric-rod Q with said lever l by a hinge-joint on pin 0.

S is a semi-rotating plate secured to and operating with the cog-wheel gand shaft f,

N is the reversvalve-stem N, said lever being engaged to the bar N bythe pin 12 passing through the slot 0" and the bifurcated end of the barN. The said bar has a rack of teeth on its upper side which engage withthe teeth on the cog-wheel g, the lower side of said bar resting andsliding on the piece It.

Now, having anticipated the operation of my invention in the definitionof its descriptive letters, I concisely and further state its operationas follows: When the workingsteam enters the port G in thereversing-valve F, the engine is working directly, or the first way. Thesteam thence passes through the port Z in the partition-plate BO, port Hin the main valve E, and alternately into each end of the cylinderthrough steam-ducts K and K, which steam-ducts serve as ports forworking and exhaust steam alternately as the main valve slides back andforth in the valve-chest, and the port H communicates alternately withthe entrance-ports to the steam-ducts K and K. The exhaust-steam passesfreely to any part of the valve-chestB around the main valveEand makesits exit therefrom into the valve-chest 0 through 'port Y, and-out ofsaid chest 0 through an opening in any convenient part of said chest 0,passing freely around the reversing-valve F. When the engine is reversedthe lever U is pushed toward the valve-chests, moving the bar N andvalve-stem N in the same direction. This carries the reversingvalve F tothe position shown by the broken lines of said valve, as indicated by afigure 2 added to its letter of designation, and closes the port Ybetween the valve-chests B and G. This position allows the working-steamto pass obliquely through the reversingvalve F by the port I (shown inbroken lines) into-the main valve-chest B, through-port X in thepartition-plate BO, thence into the cylinder through the steam-ducts Kand K alternately, while the exhauststeam .passes through the main valveE by the port H, and into the valvechest 0 by the port Z, and thencethrough the channel J, across the reversing-valve E, into thevalve-chest 0. While the bar N is moving toward the valve-chest in theoperation of reversing the engine, the plate S makes aquarter-revolution, carrying the pivot c, with its attachedconnecting-rod T, to the highest point in the-revolution, (marked c,)thus lifting the fulcrum-bar O by the pin'd, lever P by the pin 12, andthe eccentric-rod Q by the pin 0, to its maximum height, and changingthe leverage of the lever P in its relation to the eye in the piece 2'of the main valve-stem M, and thus shortening the stroke of the mainvalve E at the half-way point in the movement of the reversing-valve F.This reduces the supply of working-steam taken into the cylinder whilethe engine is moving directly or the first way, so that the reversedmovement of the engine will meet with less resistance of direct-workingsteam, while the reversingvalve F is reversing the movement of theengine. When the pin 6 is carried by a half-revolution to the otherlower point, (marked 6 and with it the connecting-rod T, the fulcrum-barO, the lever P, and the eccentric-rod Q, the full stroke of the mainvalve E is again made on the reverse movement, and a full head ofworking-steam is. obtained by a restoration of the mechanical relationof the lever P with the eye in the piece z of the main valve-stein M.The reversing-valve F may be packed at its bearing against either theupper or under surface of the valve-chest O with any suitable elasticpacking. A wedge-shaped enlargement of the lever P, near its point ofcontact with the bearing-surfaces of the eye in the piece 1', throughwhich it passes, takes up and prevents any loss of reciprocal motionwhen the said lever P stands perpendicular to the piece 2'. p

The advantages of my invention are obvivious in the simplicity ofconstruction and the ease with which the reversing movement can he made.

In the drawings, the valve-chest is located at the side of the cylinder,the valves having horizontal bearings against the steam-ports. This isanovel arrangement, and is an advantage in locomotive construction, asit permits the use of a horizontal straight-line eccentricrod from theeccentric-disk on the axle of the driving-wheels.

I claim I ,1; I11 a steam-engine, the combination of the cylinderA,valve-chests B and O, and valves E and F,with the ports and passagesG, H, I,

J, X, Y, Z, K, and K, and openings for the V inlet of working-steam andexit of exhauststeam, as described, andfor the purpose or purposesspecified.

2. In a steam-engine, the reversing mechanism consisting of thevalve-stem N and bar N, gear 9, and plate S, connecting-rod T,fulcrum-bar O, lever P, valve-stem M, sliding pieces 1' and h, andeccentric-rod Q, with all :20

their bearings, connections, and attachments, substantially asdescribed, and operated by the leverU, as and for the purpose orpurposes specified.

3. In a steam-engine, the reversing-valve F, 125

with its ports G, I, and J, communicating with valve-chests B and O, andmain valve E, and operating substantially as described, and for thepurpose or purposes specified.

4. In a steam-engine, the cylinder A, valve- 1 0 chests B and O, valvesE and F, with their bearings, connections, and attachments, subseveralports communicating with the ports stantially as described, and for thepurpose 01' 10 X, Y, and Z, and ports to steam-duets K and purposesspecified.

K, in combination with the ciireciz-acting and ALONZO FREEMAN. reversingmechanism, consisting of the Valvestems N and M, bar N, gear 9, plate S,con- Vitnesses:

heating-rod T, fulcrum-bar O, lever P, slide I J. F. CHASE, pieces; andh,and eccentric-r0c1Q,a1l with their GEO. MCDONALD.

